Manufacture of phthalocyanines



Patented Sept. 10, 1940 t 3 UNITED STATES MANUFACTURE OF PHTHALOCYANINES Albert Riley, Huddersfield, England, assignor to perial Chemicallndustries Limited, a corporation of Great Britain No Drawing; Application June 3, 1937, Serial No: 146,313- In Great Britain June 4, 1936 8 Claims. (Cl. 260-314) application of Max Wyler, Serial No. 90,008, filed July 10, 1936.

By the present invention there is obtained an improved yield, or as a further or alternative technical advantage, the reaction is caused to 10 take place smoothly at a lower temperature, and

as a consequence the shade of the resulting pigment is brighter.

In application, Serial No. 90,008 it was shown that certain metal phthalocyanines, for instance,

those of copper, iron, nickel, cobalt, chromium,

and aluminium can be made from diammonium phthalate, phthalic anhydride, phthalamide, phthalimide, and other related substances (in which also are included nuclear substitution derivatives), when the reaction thereof with the requisite metal-yielding substance is effected in a medium of urea, with or without pressure. Insofar as the organic initial material is concerned, the said copending application mentions the following as suitable: A phthalic anhydride (the term includes also the anhydrides of naphthalene-1:2- and -2:3-dicarboxylic acids) or the corresponding free acid, or a mono ether, e. g. an alkyl ether thereof, or an ammonium salt thereof, or a mono or di-amide, or imide of the said acid, or an orthocyano-benzoic acid or an ammonium salt or ester thereof. It also suggests the use of a phthalimimide as typified by phthalimimide itself (also known as imino-phthalimidine). It was further shown in that application that the reaction was facilitated, in that the yield and quality of the product were improved or the reaction caused to take place at a lower temperature, if boric acid were present in the melt.

I have now found that boric acid is not unique, but that other substances, which with boric acid, may be termed ancillary reagents, may be used, and that within this wide class there are substances of outstandingly useful properties.

' -15 According to my invention ancillary reagents are brought into the reacting mixture of a phthalic anhydride or other phthalic derivative,

urea, and a metal-yielding substance, these ancillary re-agents being substances consisting of or containing elements of the groups V and VI I of the periodic system according to Mendeleeff and having atomic numbers between 15 and 92 inclusive.

These ancillary reagents are'used in relatively so small amounts. The precise mechanism of their behaviour has not been determined. They may have a catalytic function. Be that as it may, my invention is based on my discovery that a common behaviour is shown by the substances I have classed together as ancillary agents, al- 6 though they vary in degree of activity.

The 'amount of ancillary agent is, as indicated, relatively small; itmay be from 0.1 to 5% of the weight of the entire mass of reagents. Combinations of ancillary agents may be used.

The ancillary agents vary, as has been said, in their efllciency. Thus, with ammonium molybdate a good yield of copper octa (326)-chlorophthalocyanine is obtained from .3:6-dichlorophthalic anhydride and urea, whereas with ammonium phosphate 2. smaller yield is obtained. Nevertheless, as when neither ammonium molybdate nor ammonium phosphateis present a still smaller yield is obtained, it is seen that ammonium phosphate is a useful ancillary agent. 20

The invention is illustrated but not limited by the following examples, in which the parts are by weight.

. Example 1 parts of urea are melted in an enamelled 25 iron vessel provided with a stirrer and when the temperature is -l65 C. 100 parts of phthalic anhydride are stirred in. 0.2 part of ammonium molybdate are added, followed by 25 parts of anhydrous cupric chloride, which is slowly added. The temperature rises by heat of reaction and copper phthalocyanine begins to be formed. There is some development of froth. The mixture is kept at C. until the froth subsides 35 and it is then heated at C. for two hours, at the end of which time it is too stiff to be stirred. It is cooled, powdered,'and boiled first with dilute aqueous caustic soda, then with boiling dilute aqueous hydrochloric acid. Finally it is washed with water anddried. 81 parts of copper phthalocyanine are thus obtained.

A similar good yield of copper octa (3:6)- chlorophthalocyanine is obtained when 3:6-dichloro-phthalic anhydride is used instead of 45 phthalic anhydride itself.

Instead of 0.2 part of ammonium molybdate there may be used to similar effect 1.6 parts of diammonium hydrogen phosphate, or 4 parts of tartar emetic, or 2.2 parts of tungstic acid. Am- 50 monium molybdate, for instance, may be used to advantage in conjunction with boric acid, or a compound of two active elements, e. g. ammonium borotungstate or ammonium phosphomolybdate or phospho-tungsto-molybdic acid may be used. 55

Example 2 parts of urea are melted as described in the preceding example and 150 parts of phthalic anhydride are added. Then 22.5 parts of cuprie chloride and 1.85 parts of arsenious oxide are added at -180 C. Even at this temperature copper phthalocyanine is rapidly formed. The melt is heated for two hours at -180 C. It is then cooled and treated as in Example 1. The

yield, of copper phthalocyanine is 63 parts.

'found that compounds of molybdenum are to be preferred by reason of their great activity. In the claims below the phrase a catalytic quantity shall be understood as referring to a quantity not exceeding 5% by weight of the entire reaction mass.

Instead of phthalic anhydride, phthalonitrile, or o-cyanobenzoic acid or its mono-esters or other derivatives may be used.

I claim:

1. The process of producing a metal-phthalocyanine'coloring matter which comprises heating together urea, a metalliferous reagent capable of supplying a metal selected from the group consisting of iron, nickel, cobalt, aluminum, chromium and copper, and an ortho-arylene derivative selected from the group consisting of orthoarylene anhydrides, the corresponding free acids, ammonium salts of said acids, mono-amides of said acids, di amides of said acids, the imides and imimides of said acids, the ortho-arylene-cyanocarboxylic acids, and ammonium salts of the latter, the reaction being efiected in the presence of a'catalytic quantity of an ancillary reagent containing an element selected from the group consisting of phosphorus, vanadium, arsenic, selenium, antimony, molybdenum, tungsten and bismuth.

2. A process as in claim 1, the reaction being carried out in the further presence of boric acid.

3. The process of producing a copper-phthalocyanine coloring matter, which comprises heating together urea, a copper-yielding reagent, and an ortho-arylene derivative selected from the group consisting of ortho-arylene anhydrides, the corresponding free acids, ammonium salts of said acids, monoamides of said acids, diamides of said acids, the imides and imimides of said acids, the ortho-arylene-cyano-carboxylic acids, and ammonium salts'of the latter, the reaction being carried out in the presence of a. catalytic quantity of an ancillary reagent containing an element selected from the group consisting of phosphorus, vanadium, arsenic, selenium, antimony, molybdenum', tungsten and bismuth.

4;Ihe process of producing a copper-phthalm cyanine coloring matter, which comprises heating together urea, a copper-yielding reagent, and an ortho-arylene derivative selected from the group consisting of ortho-arylene anhydrides, the corresponding free acids, ammonium salts of said acids, monoamides of said acids, diamides of i said acids, the imides and imimides of said acids,

the ortho-arylene-cyano-carboxylic .acids, and ammonium salts of the latter, the reaction being carried out in the presence of a catalytic quantity of a substance containing molybdenum.

5. A process as in claim 4, the reaction being carried out in the further presence of boric acid.

6. In the process of producing a copperphthalocyanine by heating together an orthophthalic anhydride, a reagent yielding copper, and urea, the improvement which comprises effecting the reaction in the presence of a catalytic quantity of a molybdate. I

7. In the process of producing a copperphthalocyanine by heating together an orthophthalic anhydride, a reagent yielding copper, and urea, the improvement which comprises effecting the reaction in the presence of a catalytic quantity of a molybdate and in the further presence of boric acid.

8. The process of producing copper-phthalocyanine, which comprises heating together, at a temperature between 160 and (3., substantially 100 parts of phthalic anhydride, 25 parts of cupric chloride, 120 parts of urea and 0.2 part I of ammonium molybdate, and recovering the resulting pigment.

ALBERT RILEY. 

